1. Field of the Invention
The present invention relates to an electric power generation control system for a vehicle, for controlling electric power generation by a generator using an internal combustion engine as a motive power source.
2. Description of the Related Art
Conventionally, there is known an electric power generation control system for a vehicle, which is disclosed in Japanese Laid-Open Patent Publication (Kokai) No. H2-16344. A generator mounted in the vehicle uses an internal combustion engine as a motive power source to thereby generate voltage and electric power according to supply current supplied to a coil, and the generated electric power is charged in a battery via an electrical component such, as a wire harness. In this electric power generation control system, during other than deceleration of the vehicle, the supply current to the coil is controlled to zero, whereby the generation of electric power by the generator is stopped. On the other hand, when the vehicle is decelerated, the supply current to the coil is set to an initial value to thereby start generation of electric power, and thereafter, the supply current is reduced according to a decrease in the vehicle speed, whereby the generated voltage is gradually reduced from a value corresponding to the initial value of the supply current. This gradually reduces torque for electric power generation to smoothly stop the vehicle.
The conventional electric power generation control system performs electric power generation control only by setting the supply current to the coil to the initial value to start the electric power generation, and reducing the supply current according to the decrease in the vehicle speed. Therefore, in a case where the initial value of the supply current is large and the rate of reduction of the supply current is small, a state in which the supply current to the generator is large and the generated voltage is high sometimes continues for a long time. In such a case, there is a fear that the electrical component for supplying electric power from the generator to the battery generates heat to bring itself to an overheated state in which the temperature thereof is higher than an allowable temperature, causing deterioration of the electrical component and components provided therearound. On the other hand, in order to avoid such a problem, it is envisaged to reduce the generated voltage of the generator as a whole. However, in such a case, although the overheating of the electrical component and the like can be prevented, it is impossible to charge the battery sufficiently.